While the overall prevalence of new HIV infections and mortality rate among people living with HIV (PLHIV) continue to decline in Cambodia, risky sexual behaviors and subsequent new HIV infections among transgender (TG) women continue to be of great concerns. To reduce HIV prevalence among TG women, it is crucial to track the changes in prevalence, risk behaviors, and factors associated with HIV infection to devise more responsive and tailor-made interventions. This Integrated Biological and Behavioral Survey (TG-IBBS 2016) investigates the current HIV prevalence, risky sexual behaviors, and factors associated with HIV infection among TG women in Cambodia. Where allowable, the results of this study are compared with those of the first one conducted in 2012. This study provides further evidence to confirm whether Cambodia is on track towards meeting the goals in the fight against HIV and whether the country’s “3.0” (Three Zeros) goal will be realized by 2020.